Jet nozzle

ABSTRACT

A jet nozzle for thrust vectoring has a jet pipe, at the downstream end of which are a plurality of part spherical segments which are movable from a nested position around the jet pipe into a position in which they deflect the stream of exhaust gases from the jet pipe. The movement is effected by a chain which is pushed and pulled by a linear actuator, the chain links having abutments thereon which limit the amount of flexing of the chain to a radius determined by movement of the outermost segment.

United States Patent Hall JET NOZZLE v [72] Inventor: John Matthew Hall,Bristol, England [73] Assignee: Sectretary of State for Defense in HerBritainnic Maiestys Government of the United Kingdom of Great Britain &North, Ireland, Whitehall, London, England [22] Filed: July 21, 1971[21] Appl. No.: 164,794

[30] Foreign Application Priority Data July 31, 1970 Great Britain..37,062/70 [52] U.S. CI ..239/265.35, 60/230 [51] Int. Cl. ..B64c 15/04[58] Field of Search ..239/265.I9, 265.27, 265.33, 239/265.35, 265.37,265.39; 60/228, 230

[56] References Cited UNITED STATES PATENTS 2,951,660 9/1960Giliberty..,, ..239/265.33

3,178,887 4/1965 Wilde etal. ..239/265.35 3,266,733 8/1966 Goehler..239/265.35 X 3,380,660 4/1968 Marlcowski ..239/265.27 3,531,94010/1970 Markowski ..60/230 FOREIGN PATENTS OR APPLICATIONS 1,119,12612/1961 Germany ..239/265.37

Primary Examiner-M. Henson Wood, J r'. Assistant Examiner-Thomas C.Culp, Jr. Att0rney Stevens, Davis, Miller & Mosher [5 7] ABSTRACT A, jetnozzle for thrust vectoring has a jet pipe, at the downstream end ofwhich are a plurality of part spherical segments which are movable froma nested position around the jet pipe into a position in which theydeflectthe stream of exhaust gases from the jet pipe. The movement iseffected by a chain which is pushed and pulled by a linear actuator, thechain links having abutments thereon which limit the amount of flexingof the chain to a radius determined by movement of the outermostsegment.

1 Claim, 5 Drawing Figures PATENTEDDEB i n SHEET 1 OF 2 mm mm JET NOZZLE1 This invention relates to a engines.

According to this invention a jet nozzle for a gas turbine enginecomprises a jet pipe for the flow of combustion products of the engine,a plurality of hollow sphere segments of different radius connected to acommon pivot on the jet pipe and capable of being moved between aposition in which they are nested around the downstream end of the jetpipe and a position in which they are extended to form a curvedextension of the jet pipe for the purpose of diverting the jet flow fromthe direction determined by the jet pipe itself, a chain connectedbetween the outermost of the segments, and a linear actuator fixedlysupported in relation to the jet pipe so that when the chain is pushedby the actuator the segments are moved from the nested to the extendedposition and vice versa, the chain comprising links including abutmentslimiting the flexing of the chain away fror'nthe straight to a radiusdetermined by the movement of said outermost segment.

An example of a nozzle according to this invention will now be describedwith reference to the accompanying drawings wherein:

FIG. 1 is a side elevation of the nozzle shown in an extended position.i

FIG. 2 is an enlarged section on the line lI--II in FIG.

jet nozzle for, gas turbine FIG. 3 is a view on the line Ill-III in FIG.1 but showing the nozzle in a contracted position. FIG. 4 is anenlargedplan view of the chain employed in the construction of thenozzle.

F [6.5 is a partly sectioned elevation of F IG. 4.

Referring to the drawings, there is provided a jet pipe having aconvergent tenninal portion and three hollow sphere segments ll, l2, 13of different radius and supported on a common pivot 14 on the jet pipe.The segments are movable between the extended position shown in fulllines and a nested position indicated in broken lines. In the nestedposition of the segments the flow of gas from the jet pipe issues in adirection determined by the terminal portion 15. In the extendedposition of the segments the gas flow is diverted downwards as shown at16. The segments have abutments l7, 18 so that if the outermost segment13 is moved from the nested to the extended position the other segmentsare caused to follow, and abutments 19 arranged so that if the segment13 is retracted the other segments are likewise caused to follow.

Above the jet pipe there is provided a linear actuator in the form of anair motor 20 adapted to rotate a screw 21 so as to move a nut 22 along ahollow track or guide 23. The nut has a lug 24 protruding into the guideand connected to one end of a chain 25 the other end of which isconnected to a lug 26 on the segment 13, which segment constitutes apivotal arm for transmitting motion by means of the chain.

If the motor is actuated to move the nut in the direction towards themotor the chainis being pulled into the guide and the segments are movedinto the nested position. Movement of the motor in the opposite sensecauses the chain to push the segments into the extended position.

To ensure that the chain does not collapse when prothe recess of theadjacent link and the surfaces 29,31

confront each other. The relationship between the surfaces 29,31 is suchthat when the chain is straight there is a gap 33 between them and ifthe chain is flexed in the sense causing that gap to be reduced then theeventual abutment of the surfaces 29,31 limits the angle a to whichadjacent links can be pivoted. The dimensions are made such that whenall the surfaces 29,31 of the chain are in engagement the chain takes upan arc as shown in FIG. 1 whose radius is equal to the radius swept bythe lug 26 when the segment 13 is pivoted. The lug 26 has a recesssimilar to the links for engagement by the tongue of the adjacent link.

It will be seen that the chain, as connected between the lugs 24,26 and,projecting from the guide 23, cannot be collapsed from said are becausesuch collapse would involve a reduction of the angle a between at leasttwo of the links which, as described, is made impossible by theengagement of the tongues and recesses.

Further, it will be noted that the ability of the chain to maintain thearcuate position makes it possible not to have to use a guide around thearcuate part of the chain which guide would be exposed to the exhaustgases when the segments are retracted unless the arcuate guide is itselfmade segmented and retractable but to do that would disadvantageouslyadd to the weight and complexity of the structure.

Iclaim:

1. A jet nozzle for a gas turbine engine comprising a jet pipe for theflow of combustion products of the engine, a plurality of hollow spheresegments of different radius connected'to a common pivot on the jet pipeand capable of being moved between. a position in which they are nestedaround the downstream end of the jet pipe and a position in which theyare extended to form a curved extension of the jet pipe for the purposeof diverting the jet flow from the direction determined by the jet pipeitself, a chain connected between the outermost of the segments, and alinear actuator fixedly supported in relation to the jet pipe so thatwhen the chain is pushed by the actuator the segments are moved from thenested to the extended position and vice versa, the chain comprisinglinks including abutments limiting the flexing of the chain away fromthe straight to a radius determined by the movement of said outermostsegment.

1. A jet nozzle for a gas turbine engine comprising a jet pipe for theflow of combustion products of the engine, a plurality of hollow spheresegments of different radius connected to a common pivot on the jet pipeand capable of being moved between a position in which they are nestedaround the downstream end of the jet pipe and a position in which theyare extended to form a curved extension of the jet pipe for the purposeof diverting the jet flow from the direction determined by the jet pipeitself, a chain connected between the outermost of the segments, and alinear actuator fixedly supported in relation to the jet pipe so thatwhen the chain is pushed by the actuator the segments are moved from thenested to the extended position and vice versa, the chain comprisinglinks including abutments limiting the flexing of the chain away fromthe straight to a radius determined by the movement of said outermostsegment.